So... Spore Hardening.

[AimlessMind]

Still newer to Plague, but had everything infected but Iceland and New Guinea. Had Spore Hardening for a LONG time. After I had gotten it, got symptoms boosting infectivity. Then when sufficient population infected started some lethality. Devolved Lethal since those two weren't infected. eventually killed myself off. So the question of the matter, wtf does Spore Hardening actually do cause, it doesn't randomly proc a spore spread like it seams to say?

[Elementus]

the spore spread happens as soon as you evolve the symptom not a long time after you evolve

[Olivier Batteux]

Hello,

In multiplayer modes, spores come randomly, and are not affected by any evolutions, only by waiting and by the number of infected people.

In single player mode, spores come instantly after evolving a spore ability. There is no need to wait more, you know the effect of your previous spore evolution in 2-3 days only. And you won't get more spores by waiting if you don't evolve more spore abilities.
They can be cheap if you take pathostasis, but they are not infinite or renewable. So you must enter in enough countries by usual ways (birds 2, air, water) to be able to fix the last missing ones by spores.

It's interesting to use a few spores early to start covering several continents early, and to keep enough slots available for the late game to be able to fix the late islands.

You can see on these tutorials how I have used spores with fungus :

Normal level :
https://www.youtube.com/watch?v=1AVfJlT7BLA
https://www.youtube.com/watch?v=I2IYK_QZWXI
https://www.youtube.com/watch?v=HRShpbhtdr4

Mega-brutal level :
https://www.youtube.com/watch?v=ziTYkNEnKwk
https://www.youtube.com/watch?v=BmgYd4qsDnQ